com.datatorrent.stram.engine.RecoverableInputOperator.java Source code

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Here is the source code for com.datatorrent.stram.engine.RecoverableInputOperator.java

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/**
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *
 *   http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing,
 * software distributed under the License is distributed on an
 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
 * KIND, either express or implied.  See the License for the
 * specific language governing permissions and limitations
 * under the License.
 */
package com.datatorrent.stram.engine;

import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import org.apache.commons.lang.builder.ToStringBuilder;
import org.apache.commons.lang.builder.ToStringStyle;

import com.datatorrent.api.Context.OperatorContext;
import com.datatorrent.api.DefaultOutputPort;
import com.datatorrent.api.InputOperator;
import com.datatorrent.api.Operator;
import com.datatorrent.bufferserver.util.Codec;
import com.datatorrent.common.util.BaseOperator;

/**
 *
 */
public class RecoverableInputOperator implements InputOperator, Operator.CheckpointNotificationListener {
    public final transient DefaultOutputPort<Long> output = new DefaultOutputPort<>();
    private long checkpointedWindowId;
    private transient boolean firstRun = true;
    private transient boolean first;
    private transient long windowId;
    private int maximumTuples = 20;
    private boolean simulateFailure;

    private static final Map<Long, Long> idMap = new HashMap<>();
    private static long tuple = 0;
    public static List<Long> emittedTuples = new ArrayList<>();

    public void setMaximumTuples(int count) {
        maximumTuples = count;
    }

    public static void initGenTuples() {
        tuple = 0;
        idMap.clear();
        emittedTuples.clear();
    }

    @Override
    public void emitTuples() {
        if (first && maximumTuples > 0) {
            // only emit tuples once per window (first is reset to true in beginWindow())
            logger.debug("emitting {}", Codec.getStringWindowId(windowId));
            Long etuple = idMap.get(windowId);
            if (etuple == null) {
                etuple = tuple++;
                idMap.put(windowId, etuple);
            }
            output.emit(etuple);
            emittedTuples.add(etuple);
            first = false;
            maximumTuples--;
        }
    }

    @Override
    public void beginWindow(long windowId) {
        this.windowId = windowId;
        first = true;
    }

    @Override
    public void endWindow() {
    }

    @Override
    public void setup(OperatorContext context) {
        firstRun = (checkpointedWindowId == 0);
        logger.debug("{}", this);
    }

    @Override
    public void teardown() {
    }

    @Override
    public void checkpointed(long windowId) {
    }

    @Override
    public void committed(long windowId) {
        logger.debug("{}, windowId={}", this, Codec.getStringWindowId(windowId));
        if (simulateFailure && firstRun && checkpointedWindowId > 0 && windowId > checkpointedWindowId) {
            throw new RuntimeException("Failure Simulation from " + this);
        }

        // we have emitted enough tuples and we have tested recovery, so we can shutdown once we have emitted enough.
        if (maximumTuples == 0) {
            BaseOperator.shutdown();
        }
    }

    private static final Logger logger = LoggerFactory.getLogger(RecoverableInputOperator.class);

    void setSimulateFailure(boolean flag) {
        simulateFailure = flag;
    }

    @Override
    public void beforeCheckpoint(long windowId) {
        if (checkpointedWindowId == 0) {
            checkpointedWindowId = windowId;
        }
        logger.debug("{}, windowId={}", this, Codec.getStringWindowId(windowId));
    }

    @Override
    public String toString() {
        return new ToStringBuilder(this, ToStringStyle.SHORT_PREFIX_STYLE).append("firstRun", this.firstRun)
                .append("checkpointedWindowId", Codec.getStringWindowId(checkpointedWindowId)).toString();
    }
}